In the recording industry, it is common practice to duplicate cassette tape recordings by supplying one or more "slave" recorders with recording signals from a single master transport on which a master cassette tape is played. The master and slave recorders are operated at high speeds to provide duplication at sixty-four times the normal tape playback speed, i.e., at 64:1 duplication ratios, thus significantly increasing the recording capacity of the master/slave duplicating arrangement. As can be appreciated, some means for monitoring the performance of the slave recorders is highly desirable. Prior art performance monitoring systems frequently utilize a one-track test or playback head which detects the signals being duplicated onto the slave tape. The playback head is placed in the path of the tape leaving the slave recording head to provide immediate playback of the duplicated signals. In this manner, proper quality control measures can be instituted as indicated to correct any inaccuracies found in the duplicated tapes.
Although enhancing quality control during the tape duplication process, prior art performance monitoring systems suffer from several drawbacks which limit overall system effectiveness. Inasmuch as prior art playback heads generally have single track configurations, track selection on the four-track cassette tapes commonly employed in the recording industry can only be achieved by changing the vertical position of the playback head. Changes in vertical head position can in turn create zenith errors in the playback signal obtained from the head. Prior art monitoring systems also make use of the existing tape take-up tension in the slave recorder to establish tape-to-playback head contact. Such existing take-up tension often results in insufficient playback head contact pressure, causing low playback output signals and unstable signal levels at the high signal frequencies associated with high duplication ratios. Adequate playback signal equalization is accordingly difficult to obtain and the playback signals must be checked on a real time playback deck, which latter procedure greatly increases the amount of labor required to carry out the tape duplicating process. Hence, it would be of great benefit to provide a performance monitoring system which eliminates the aforementioned problems and which could be adpated to fit existing slave recorders with minimum alteration of the slave recorder structure.